The first deadly incident happened when three children aged 5-8 found a toy-like explosive device in Sayed Abad district on Sunday afternoon and began playing with it, but the device went off suddenly, killing two on the spot and injuring the other one, the statement added.
An hour later that another child was killed as a mine exploded in Sayed Abad's neighboring Dehmirdad district, according to the statement.
A similar blast claimed a child's life and injured another in Sayed Abad district on Friday.
Afghanistan is reportedly one of the most mine-contaminated countries globally as dozens of people, mostly children, were killed and maimed every month due to blasts of unexploded ordnances left over from the past four decades of wars and civil strife.